Silicone polymers have many unique properties, such as wide service temperature range; low viscosity change versus temperature; low flammability; shear stability; chemical inertness; oxidative stability; UV stability; low toxicity; and the like. These properties have facilitated their adoption as dielectric, hydraulic, heat transfer, power transmission and damping fluids. Silicone polymers have also found application as additives incorporated into plastics and rubbers as process and release aids, into coatings for flow and level control and into process streams as antifoams. Other unique properties have led to their introduction in acoustical applications such as ultrasonic sensor and sonar buoys. This proliferation of applications has engendered many improvements and refinements of silicone polymers.
Anionic polymerization of cyclosiloxanes, particularly hexamethylcyclotrisiloxane (D.sub.3) and octamethyltetrasiloxane (D.sub.4), has been reported previously. It is known that D.sub.3 polymerization does not occur in hydrocarbon solvents. C. L. Frye, R. M. Salinger, F. W. Fearon, J. M. Klosowski and T. deYoung, J. Org. Chem., 35, 1308 (1970). Although the anionic species was formed (Bu--Si(CH.sub.3).sub.2)--O--Li.sup.+), it did not polymerize. Addition of a polar promoter, such as THF, diglyme, or DME then stimulated the polymerization. J. M. Yu, D. Teyssie, R. B. Khalife and S. Boileau, Polymer bulletin, 32, 35-40 (1994). The resultant polymer anion PDMS--O--Li.sup.+ can then be protonated to afford PDMS--OH, capped with a silicon halide (R.sup.3 R.sup.4 R.sup.5 --Si--X) to afford PDMS--O--SiR.sup.3 R.sup.4 R.sup.5, or coupled with suitable coupling agents (SiCl.sub.4, Me.sub.2 SiCl.sub.2, HSi(OMe).sub.3) to afford (PDMS).sub.n, wherein n is the number of coupling agent functionalities. In spite of considerable synthetic efforts, however, there are few good ways to affix functionality to the termini of the silicone polymers.